A large analysis looked at hundreds of factors that can affect the risk of heart failure, and in particular one dietary factor is associated with a lower risk: drinking coffee.
Heart failure, sometimes called congestive heart failure, occurs when the heart muscle weakens and blood can no longer pump efficiently. It can be caused by high blood pressure, heart valve disease, heart attack, diabetes and other diseases and conditions.
The analysis included extensive, decades-long data from three large health studies with 21,361 participants, and uses a method called machine learning that uses computers to find meaningful patterns in large amounts of data.
“Usually, researchers choose things they suspect are risk factors for heart failure – such as smoking – and then look at smokers versus non-smokers,” said senior author Dr. David P. Kao, an assistant professor of medicine at the university. said. of Colorado. “But machine learning identifies variables that predict whether increased or decreased risk, but which you did not necessarily think of.”
Using this technique, dr. Kao and his colleagues found 204 variables associated with the risk of heart failure. They then looked at the 41 strongest factors, which include, among others, smoking, marital status, BMI, cholesterol, blood pressure and the consumption of different foods. The analysis is in Circulation: Heart Failure.
In all three studies, drinking coffee was stronger than any other dietary factor associated with a reduced long-term risk of heart failure.
Drinking one cup a day or less had no effect, but two cups a day reduced a reduced risk by 31 percent and three cups or more by 29 percent. There were not enough subjects who drank more than three cups daily to know if more coffee would further reduce the risk.
This is not the first study to find health benefits of drinking coffee. “In other studies, drinking coffee has also been associated with a reduced risk of stroke and heart disease,” said Dr. Kao said, although we did not find it in our study. “
The study could not take into account different types of coffee or brewing methods or the use of additives such as sugar or cream. There was no association between a reduced risk of heart failure and drinking decaffeinated coffee.
Caffeine may be an important factor, the authors suggested, but the mechanism for the effect is not known. The study did not investigate the effect of tea or other caffeinated foods.
Unlike conventional observational studies that start with a hypothesis and then develop evidence for it, this machine learning analysis started with no initial hypothesis. Dr. Harlan Krumholz, a professor of medicine at Yale who was not involved in the work, calls the approach ‘innovative’, but notes that one limitation was that ‘many other behaviors are likely to be due to coffee consumption, and it is difficult to disrupt the specific effect of coffee from other things that go along with it. ”
Should you start drinking coffee or increase the amount you are already drinking to reduce your risk of heart failure? “We do not know enough from the results of this study to recommend it,” said Dr. Kao said, adding that additional research would be needed. “It would be helpful if we could determine if drinking an extra cup would prevent certain complications.”